Researchers from Germany's Karlsruhe Institute of Technology (KIT) and Shanghai University developed a new high-efficiency exciplex deep-blue OLED emitter material. The researchers say that this new materials achieves a external quantum efficiency (EQE) of 20.35% - a new world record for deep-blue emission.
The researchers explain that their exciplex strategy is based around a new molecule type with carbazole and triazine fragments linked by a silicon atom. The molecules assemble into nanoparticles which emit light in a different mechanism compared to standard single-molecule emitters. The energy levels of the electron-donating carbazole fragments and electron-accepting triazine fragments can be adjusted independently of each other to enable highly efficiency and stable red, green and blue OLED emitters.
Researchers from KIT have worked on exciplex OLEDs for many years. Exciplex technology is also the basis of SEL's successful ExTET OLED technology.